#include "cal.h"

int myerron = 0;

int add(int x,int y)
{
    return x+y;
}

int sub(int x,int y)
{
    return x - y;
}

int mul(int x,int y)
{
    return x*y;
}

int div(int x,int y)
{
    if(y==0)
    {
        myerron = -1;
        return myerron;
    }
    return x/y;
}